DNA- and RNA- hydrolysed antibodies from human milk and its biological role
Kanyshkova, T.G.; Semenov, D.V.; Vlasov, A.V.; Khlimankov, D.I.; Baranovskiĭ, A.G.; Shipitsyn, M.V.; Iamkovoĭ, V.I.; Buneva, B.N.; Nevinskiĭ, G.A.
Molekuliarnaia Biologiia 31(6): 1082-1091
1997
ISSN/ISBN: 0026-8984 PMID: 9480422 Document Number: 477155
Catalytically active antibodies, or abzymes, are known to appear in the blood of mammals immunized with analogues of transition state complexes, or in human autoimmunization resulting from autoimmune diseases. This study reveals for the first time that class G immunoglobulins (homogeneous preparations of Fab- and F(ab)2-fragments) from the milk of healthy mothers purified by chromatography on consecutively protein A sepharose, DEAE cellulose, gel filtration and DNA cellulose, can hydrolyze DNA and RNA. The ability to hydrolyze DNA and RNA proved to be a natural property of class G immunoglobulins determined by their light chains. Substrate specificity of human milk abzymes differed significantly from that of eukaryotic DNases, pancreatic ribonuclease A, as well as other known human RNases and IgG-abzymes from the blood of patients with autoimmune disorders. Taking into consideration the protective function of milk antibodies in creating passive immunity of newborns, it is suggested that milk abzymes can play an important role in baby protection mechanisms by degrading viral and bacterial nucleic acids.